AugstWest writes: "In Pennylvania, they tend to come up with some very weird and interesting ideas. Chocolate rivers, the very first movie theater, the first gay President of the US But how about a space drive that doesn't require propellant?

Called the QDrive, it's a resonating cavity with design features that redirect the radiation pressure exerted in the cavity to create a radiation pressure imbalance on the cavity. This differential in radiation pressure generates an unbalanced force that creates thrust. This cavity produces — wait for it — thrust without use of propellant. Skeptical? They've posted the theory. Or check out the numerical models for yourself. And of course, they wouldn't go public without some experimental results."